docs(fromEvent): get click events from document, rather than button
docs(fromEvent): get click events from document, rather than button

hi.
`Error: button is not defined`
`Error: clicks$ is not defined`
benlesh/RxJS,ReactiveX/rxjs,Brocco/RxJS,trxcllnt/RxJS,trxcllnt/RxJS,ReactiveX/rxjs,benlesh/RxJS,kwonoj/RxJS,martinsik/rxjs,benlesh/RxJS,martinsik/rxjs,ReactiveX/RxJS,Brocco/RxJS,benlesh/RxJS,kwonoj/RxJS,kwonoj/RxJS,ReactiveX/RxJS,martinsik/rxjs,ReactiveX/RxJS,trxcllnt/RxJS,martinsik/rxjs,ReactiveX/rxjs,Brocco/RxJS,kwonoj/RxJS,trxcllnt/RxJS,Brocco/RxJS,ReactiveX/RxJS,ReactiveX/rxjs